Nonviolent action has accomplished many things, it is just that nowdays the ruling class is mostly desensitized to protest. If you want to change society through nonviolent action, your action needs to convince others to support you. You need to convice the ruling class and all who help them to give in to your demands.
Modern day peaceful protests do nothing because they dont have any credibility. The rich rightfully believe that they can ignore you and nothing else will happen. Nonviolent protests are just one way to send a message, and I think the most important thing that this ceo killing has done for us is that it sent a message.
Our systems and hierarchies do often support the oligarchy, but that does not mean every single individual supports the oligarchy, or that every single thing our systems do are meant to advance the goals of the ultra rich. Sometimes individuals who participate in these systems do malicious compliance, sometimes they don’t comply at all.
In this case there could be someone high-up who is empathetic(or a group of empathetic people unaware of each other, their actions adding up) whose decisions led to this happening, or this could have just been a dumb decision, who knows.